Compensation-pendulum



(No Model.)

B. R. MALMBORG.

. GOMPENSATION PENDULUM.

' No. 472,624. Patented Apr. 12, 1892.

WIT N58858: INVE/VTUR: W W

-Qwvwk mm (i 4% ATTORNEY.

UNITED STATES PATENT OFFICE.

ERNST R. MALMBORG, OF ST. LOUIS, MISSOURI, ASSIGNOR, BY MESNE ASSIGN-MENTS, TO THE NEIV YORK ELECTRICAL DEVICE COMPANY, OF VIRGINIA.

COMPENSATlON-PENDULUM.

SPECIFICATION forming part of Letters Patent No. 472,624, dated April12, 1892.

Application filed December 11, 1889. Renewed October 14, 1891. SerialNo. 408,662. (No model.)

To all whom it may concern.-

Be it known thatI, EENsT R. MALMBORG, of the city of St. Louis,in theState of Missouri, have invented a new and useful Improvement inPendulums; and I do hereby declare that the following is a full andexact description thereof, reference being had to the accompanyin gdrawings, and to the letters of reference marked thereon, making a partof this specification.

This invention relates to a compensating or self-adjusting pendulumwhich shall remain constant in its length and consequently be isochronalin its movement irrespective of changes of temperature.

It consists in the novel means hereinafter described and claimed,whereby the normal length of the pendulum is automatically maintainedWithout change, notwithstanding the variations in temperature to whichit is exposed.

In the accompanying drawings, Figure l is a front view in elevation ofmy improved compensatin g pendulum; Fig. 2, a cross-section in line soas, and Fig. 3 an irregular cross-section in line 3 y of Fig. l.

A represents the pendulum-rod. Bis a compound cross-bar secured to itslower end, and which is composed of two parallel strips 0 (Z of equalsize, the one of brass, zinc, or silver and the other of steel orplatinum, or of such other two metals or metallic alloys as expand andcontract unequally under changes of temperature. The two strips are soplaced as that the strip d, having the greatest range of expansion andcontraction, shall lie under the strip 0, whose range is more limited,and they are united together by any suitable meansas, for example, bysoldering the one to the other-so as to form in effect a single compoundbar. This compensating bar B is preferably made rectangular incross-section and is passed through and secured at the middle of itslength within a rectangular socket E, fixed to the lower end of the rodA.

F F are hangers mounted to slide freely upon each end of the compoundcompensating bar B. G is a metallic weight-rod of the same length assaid bar, suspended from these hangers parallel therewith and a shortdis is prevented by means of a pin H, projecting from the end of thependulum-rod A in line with its axis into an aperture pierced throughthe middle of the length of said rod G. The middle of the rod is therebyleft free to play vertically upon the guide-pin H to and from thecompensating bar B, and the hangers are left free to be movedlongitudinally upon the bar and rod. These hangers may be moved andadjusted upon the compensating bar B by any suitable means-as, forinstance, by

means of screws J J, carried parallel with the bar 13 and rod G andintermediate the two through threaded apertures in the hanger. The innerend of each screw is made to engage a lug or offset it upon theweight-rod G,

so as to be free to revolve independently therein and yet be attachedthereto, and its outer end projects through and engagesin like manner alug or offset Z,fixed to the outer end of the rod, in which it is alsofree to rc- Volvo loosely. The outer end of each screw is furnished witha milled head M, by means whereof it may be easily revolved, and therevolution of the screw will operate to move the hanger through which itpasses to or from the inner lug 7.: and the middle of the rod. By thismeans the position of the hangers with reference to the pendulum-rod A,and consequently the proportion of the length of the compound bar B tobe embraced between the 8 5 pendulum-rod and the hanger, is very readilyadjusted. The pendulum is completed in customary form by means of aweight or bob N. This bob is secured to the middle of the weightrod Gcentrally in line with the axis of the go pendulum-rod A by means of arod P, fixed to said rod G at a right angle thereto and upon which theweight is free to slide. It is adjusted in the customary manner to andfrom the weight-rod by a nut R, screwing upon the lower end of saidweight-rod P.

In the operation of this device an increase of temperature sufficient toelongate the pendulu m-rod A will operate to cause the lower member (Zof the compound compensating bar B to expand and lengthen, and therebybend the I bar, so as to. lift the two hangers F Fand with them the rodG, carrying the weight or bob N of the pendulum, while if thetemperature be reduced the opposite effect will be produced and thecontraction of the member 7 d of the compensating bar will lower thepensating bar B, the hangers F F, sliding loosely upon the two ends ofthe bar, the weight-rod G, suspended loosely in said hangers, the singlecentral guide-pin P, projecting from the compensating bar into a centralsocket in the weight-rod, and the adjustingscrews J J, working throughthreaded apertures in the hangers and engaging at their inner ends lugs11; is, secured to the weight-rod, substantially in the manner and forthe purpose herein set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ERNST R. MALMBORG.

Witnesses:

W. N. BARRON, BEN S.- WASH.

